US8320967B2 - User location based switching between diversity and multiplexing - Google Patents

User location based switching between diversity and multiplexing Download PDF

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US8320967B2
US8320967B2 US12/967,967 US96796710A US8320967B2 US 8320967 B2 US8320967 B2 US 8320967B2 US 96796710 A US96796710 A US 96796710A US 8320967 B2 US8320967 B2 US 8320967B2
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threshold
base station
determined
edge distance
multiplexing
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US20120149416A1 (en
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Sairamesh Nammi
Narendra Tilwani
Venkata Alapati
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Telefonaktiebolaget LM Ericsson AB
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0621—Feedback content
    • H04B7/063—Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection

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  • Technical field of present disclosure relates to method, apparatus and system for switching between multiplexing and diversity, and in particular to switching between diversity and multiplexing based on a location of the user.
  • Multiple antennas at the transmitter and receiver increases the capacity in a wireless communication system.
  • the received signal quality can be increased due the diversity gain.
  • the data rate of the system can be increased due to multiplexing.
  • one particular mode is not always suitable in a wireless system. Thus, it is often a good practice to switch between diversity and multiplexing.
  • expected spectral efficiency and/or capacity can be computed at the base station from pilot measurements for each individual communication mode—diversity, adaptation, or multiplexing. Based on the computed efficiency/capacity, it can be decided whether to use diversity or multiplexing.
  • a problem associated with the conventional method is that simply computing the efficiency/capacity at the base station does not fully take into account the environmental conditions that can affect the wireless communication between a UE and the base station.
  • a non-limiting aspect of the disclosed subject matter is directed to a method to communicate between a base station and a user equipment of a wireless communication system.
  • the method may be performed at a base station capable of transmitting over multiple antennas.
  • it is determined whether the user equipment is located within a threshold edge distance from an edge of a cell corresponding to the base station. When the user equipment is determined to be located within the threshold edge distance, diversity is chosen.
  • the base station is capable of transmitting over multiple antennas.
  • the base station includes a communication unit, a UE location determination unit, and a communication mode determination unit.
  • the communication unit is configured to communicate with the user equipment
  • the UE location determination unit is configured to determine whether the user equipment is located within a threshold edge distance from an edge of a cell corresponding to the base station
  • the communication mode determination unit is configured to choose diversity for transmission from the base station to the user equipment when the user equipment is determined to be located within the threshold edge distance.
  • FIG. 1 illustrates an example of a wireless communication system layout with base station, corresponding cells, and user equipments
  • FIG. 2 illustrates a throughput of a cell sector for different modes of communication
  • FIG. 3 illustrates a throughput at cell edge for the different modes
  • FIG. 4 illustrates a flow chart of an example process for switching between diversity and multiplexing
  • FIG. 5 illustrates an example of a cell divided into sectors
  • FIG. 6 illustrates a flow chart of an example process for determining whether a user equipment is close to an edge of a cell
  • FIG. 7 illustrates a flow chart of another example process for determining whether a user equipment is close to an edge of a cell
  • FIG. 8 illustrates a flow chart of yet another example process for determining whether a user equipment is close to an edge of a cell
  • FIG. 9 illustrates a flow chart of another example process for switching between diversity and multiplexing
  • FIG. 10 illustrates a flow chart of an example process for adaptively choosing between diversity and multiplexing
  • FIG. 11 illustrates a cell divided into different regions
  • FIG. 12 illustrates an example embodiment of a base station.
  • block diagrams herein can represent conceptual views of illustrative circuitry embodying principles of the technology.
  • any flow charts, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
  • processors may be provided through dedicated hardware as well as hardware capable of executing associated software.
  • functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared or distributed.
  • explicit use of term “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, and may include, without limitation, digital signal processor (shortened to “DSP”) hardware, read only memory (shortened to “ROM”) for storing software, random access memory (shortened to RAM), and non-volatile storage.
  • DSP digital signal processor
  • ROM read only memory
  • RAM random access memory
  • 3GPP is primarily used as examples for explanation purposes. However, the scope of this disclosure is not limited to the set of 3GPP wireless network systems and can encompass many domains of wireless network systems.
  • a problem with the existing method to switch between diversity and multiplexing is that the environmental conditions that can affect the wireless communication between a UE and a base station (BS). For example, it is generally known that noises and interferences impact the quality of the radio link between a BS and a UE.
  • FIG. 1 which illustrates a layout of an example wireless communication system 100 .
  • FIG. 1 which illustrates a layout of an example wireless communication system 100 .
  • many of the elements and functions a typical wireless communication system are not illustrated.
  • elements such as the core network nodes, home location registers, gateways, and so on are not illustrated so as to minimize clutter.
  • the figures in this disclosure are exemplary and should not be taken to be limiting.
  • the system 100 includes multiple BSs 120 , 122 , 124 serving corresponding coverage areas or cells 110 , 112 , 114 .
  • UEs 130 , 135 are within cell 110 , and thus it can be assumed that the BS 120 is the serving BS for UEs 130 , 135 .
  • BSs 122 , 124 are the respective serving BSs for UEs 132 , 134 .
  • focus will be on the BS 120 and the UEs 130 , 135 it serves bearing in mind that the discussions that follow will likely apply with equal validity to the BSs 122 , 124 as well as to the UEs 132 , 134 .
  • the UE 130 is illustrated to be located close to its serving BS 120 .
  • the radio link between the BS 120 and the UE 130 is likely to be of good quality. That is, the signal-to-interference-and-noise ratio (SINR) of this radio link is likely to be high.
  • SINR signal-to-interference-and-noise ratio
  • UE 135 on the other hand is illustrated to be located fairly close to the edge of cell 110 , i.e., close to the limits of the coverage area of BS 120 .
  • the radio link between BS 120 and UE 135 is likely to suffer from noises.
  • interferences due to transmissions from neighboring base station 122 , 124 may be substantial.
  • the radio link quality, at least in the downlink direction, between BS 120 and UE 135 will be low, e.g., link's SINR will be low.
  • link's SINR will be low.
  • due to the proximity of the UE 134 to the UE 135 there may be significant interferences in the uplink direction from the UE 135 to the BS 120 as well.
  • multiplexing will increase the data transmission rate over using diversity generally. This is acceptable when the link quality between the UE and the BS is good.
  • multiplexing may be used as the communication mode between BS 120 and UE 130 in FIG. 1 .
  • FIG. 2 illustrates a throughput of a cell sector for different modes of communication—Alamouti, cyclic delay diversity (CDD), and open loop multiple-input multiple-output (MIMO).
  • Alamouti space-time codes are typically used to achieve transmit diversity (rank 1).
  • CDD is also a way to achieve single-rank transmit diversity.
  • Open loop MIMO is generally seen as an adaptive way to achieve transmission ranks greater than one (i.e. multiplexing). Higher the rank, greater the degree of multiplexing, and hence, greater the peak rate.
  • FIG. 2 shows that the adaptation mode results in a better throughput than either of the individual modes. That is, multiplexing results in a better throughput than the single-rank modes.
  • the multiplexing rank can be adapted generally such that as the UE is located closer to the cell center, the transmission rank can be correspondingly increased.
  • the data throughput may actually be better when a lower rank transmission is used.
  • diversity may result in a better overall throughput than multiplexing.
  • high rank transmissions can achieve high peak rates.
  • high rank also results in the coverage being correspondingly reduced.
  • lower rank transmissions result in greater coverage.
  • rank 1 (diversity) transmissions from the BS 120 will likely be the best in terms of throughput. This is confirmed in FIG. 3 which shows that at the cell edge, diversity has the best throughput performance.
  • the location of the user i.e., the location of the UE
  • an exemplary scheme is proposed in which the communication mode between a BS and a UE is chosen based on the UE's location. That is, the user location is considered in the proposed scheme. This is unlike the existing method in which the user location is not considered. When the user location is not considered, the cell edge user throughput can be negatively impacted as seen in FIG. 3 , which in turn reduces the coverage.
  • the proposed scheme can replace the existing method. It is also contemplated that the proposed scheme can be combined with the existing method.
  • FIG. 4 illustrates a flow chart of an example process or method for choosing a communication mode between a base station and a user equipment.
  • the method 400 may be performed at the base station of a wireless communication system, e.g. the BS 120 , to wirelessly communicate with the user equipments it serves, e.g. UE 130 , 135 .
  • the communication mode between a base station and one UE can be independent of the communication mode between the same base station and a different UE.
  • diversity mode may be chosen for a radio link between the BS 120 and the UE 135 (referred to as the “first radio link” for ease of reference) while multiplexing may be chosen for a radio link between the BS 120 and the UE 130 (referred to as the “second radio link” also for ease of reference).
  • the ranks of radio links can be independent of each other.
  • the ranks of both the first and second radio links may indicate multiplexing (rank>1), but differ in the rank level.
  • the method 400 should be taken as being independently applicable for each BS-UE radio link.
  • the communication mode is assumed to be dynamic in that the mode can change depending on the circumstances. For example, as the UE 130 moves away from the BS 120 , the first radio link's rank can be reduced. Thus, the method 400 should also be taken as being independently applicable for a particular BS-UE radio link at different times.
  • the method 400 will be described with reference to the BS 120 and the UE 130 .
  • the BS 120 determines the location of the UE 130 (step 410 ).
  • the BS 120 determines whether the UE 130 is located within a threshold edge distance from the edge of the cell 110 (step 420 ).
  • the BS 120 chooses diversity (rank 1) for the first radio link at least for the downlink transmission to the UE 120 .
  • the BS 120 chooses multiplexing (rank>1) for the first radio link at least for the downlink transmission.
  • the cell 110 corresponds to the radio coverage area of the BS 120 .
  • the threshold edge distance is some distance from the cell's edge in which diversity is enforced. Note that the threshold edge distance can be particular to each cell, i.e., it need not be the same for all cells. For example, the threshold edge distance for a relatively small cell (e.g., corresponding a base station in an urban area) may be small as compared to the distance for a relatively large cell (e.g., corresponding a base station in a rural area).
  • the threshold edge distance may change over time.
  • the threshold distance may be set closer to the edge during times of low demand (e.g., during sleeping hours, less interference likely) and set further from the edge during times of high demand (e.g., during business day, more interference likely).
  • the threshold edge distance can be set manually or be set automatically.
  • the term “cell” is to be taken broadly to mean a coverage area. This is explained with to FIG. 5 which illustrates a cell divided into three sectors. For a variety of reasons, it is fairly common to sectorize a cell in which each sector is essentially treated separately even though all sectors are served by the same base station. Thus, in at least one aspect of the present disclosure, each sector can be viewed as a separate “cell”, i.e., as a separate coverage area. Thus, the threshold edge distance of sector 1 is not necessarily the same as the threshold edge distance of sector 2 or of sector 3 .
  • the BS 120 determines in step 420 whether or not the UE 130 is within the threshold edge distance (whether or not the UE 130 is close to the edge). If the UE 130 is GPS capable, it may provide its geographical location in a report to the BS 120 from which the BS 120 may make the determination. The geographical location may be determined in other ways such as through triangulation.
  • FIG. 6 illustrates one example process in which the step 420 may be implemented.
  • the quality of the radio link between the BS 120 and the UE 130 is used as a basis to determine whether or not the UE 130 is close to the cell's edge.
  • the BS 120 receives a radio link report from the UE 130 regarding a radio link between the BS 120 and the UE 130 (step 610 ). Based on the radio link report, the BS 120 determines the link quality of the radio link (step 620 ). The BS 120 then determines whether the link quality is lower than a threshold link quality (step 630 ). When the link quality is determined to be is lower than the threshold link quality, the BS 120 determines that the UE 130 is located within the threshold edge distance (step 640 ). Conversely, when the link quality is not determined to be lower than the threshold link quality, the BS 120 determines that the UE 130 is not located within the threshold edge distance (step 650 ).
  • the threshold link quality is correlated to the threshold edge distance.
  • the threshold edge distance of one cell is not necessarily dependent on the threshold edge distance another cell, the threshold link qualities of different cells need not be dependent as well. Also just as the threshold edge distance of one cell can by dynamic, the same can be said of the threshold link quality of the cell.
  • the radio link quality can be expressed in multitudes of ways.
  • SINR is one measure of the link's quality.
  • Others measures include SNR, error rates (bits, frames, packets, etc.), retransmission rates (e.g., related to ARQs), MCS, and even the rank assigned to the UE.
  • the radio link quality can be expressed in any combination of these measures and any other individual quality measures.
  • step 630 it is indicated that whether or not the link quality is lower than the threshold link quality is determined.
  • the direction of comparison should be adjusted or otherwise accounted for depending on the particular measurement. For example, if an error rate is used; then the inequality in step 630 should be reversed or the reciprocals of the error rate should be used as the link quality measurement.
  • FIG. 7 illustrates another example process for implementing step 420 .
  • the process of FIG. 7 also uses information the UE provides to determine whether or not the UE is located close to the cell edge.
  • the number of neighboring BSs detected by the UE is used.
  • the logic is as follows. Before a handoff occurs, a UE typically sends a measurement report or multiple of such reports to the serving BS, which indicates that the UE is close to the cell boundary and is likely to handoff to other cells.
  • the measurement report typically contains information about the neighboring base stations, and may also include a measurement of the signal power emanating from the base stations. For example, in 3GPP, the UE can report to the serving eNB the RSRP levels of the neighboring eNBs as seen by the UE.
  • a high number of detected neighboring BSs is an indication that the UE is close to the cell edge.
  • the BS 120 receives a neighbor report from the UE 130 regarding other base stations neighboring the BS 120 (step 710 ).
  • the neighbor report may include information of the BSs 122 and/or 124 .
  • the BS 120 determines the number of neighboring base stations (step 720 ).
  • the BS 120 determines whether the number of neighboring base stations is higher than a threshold neighbors number (step 730 ).
  • the BS 120 determines that the UE 130 is located within the threshold edge distance (step 740 ).
  • the link quality is not determined to be higher than the threshold neighbors number
  • the BS 120 determines that the UE 130 is not located within the threshold edge distance (step 750 ).
  • threshold neighbors number is correlated to the threshold edge distance.
  • threshold neighbors number of one cell need not be dependent on another cell and can dynamically change.
  • the neighbor report can also include the power level of the neighboring base stations as detected by the UE.
  • Two different UEs at the same location may detect different number of base stations because one is more sensitive than the other. When this occurs, the neighbor reports from the two UEs may not be similar even though they are similarly located. If the total number of detected neighboring base stations is used for comparison in step 730 , the higher sensitive UE may be unnecessarily forced into a lower rank communication mode simply because it is able to detect weak signals that in reality may not be a significant source of interference.
  • each neighboring base station in the neighbor report whose signal level is higher than a threshold neighbor level is counted towards the number of neighboring base stations and others are ignored.
  • the setting of the threshold neighbor level for at least one base station can be independently set from other base stations, and the level for at least one cell may be adjusted dynamically.
  • FIG. 8 illustrates yet another example process implement step 420 .
  • the signal(s) from the UE is (are) measured at the BS to determine whether or not the UE is close to the cell edge.
  • weaker signals indicate that the UE is farther away from the BS and consequently closer to the cell edge, and vice versa.
  • the BS 120 measures the UE signal level of the signal transmitted from the UE 130 (step 810 ), and determines whether or not the UE signal level is below a threshold UE level (step 820 ). If so, the BS 120 determines that the UE 130 is located within the threshold edge distance (step 840 ). Otherwise, the BS 120 determines that the UE 130 is not located within the threshold edge distance (step 850 ).
  • the UE signal that is measured may be the UE's SRS or its pilot signal.
  • the base station typically controls the transmission power level of the UEs within its serving area so as to minimize interferences while maintaining some acceptable level of service.
  • the strength of the measured signal by itself may not be an accurate indication of the UE's location.
  • the BS 120 can also take into account the level at which the UE 130 transmits since the BS 120 can instruct the UE 130 to transmit at a particular level.
  • a UE when a UE first enters a cell of a base station, no transmission control has yet taken place, and thus the UE will transmit its pilot signal, e.g., a sounding reference signal (SRS), at a default power level.
  • the signal from the UE 130 may be measured in step 810 prior to the BS 120 instructing the UE 130 to adjust its transmission power, and that measured level may be used for comparison in step 820 .
  • the BS 120 may simply instruct the UE 130 to transmit at a predetermined power level (step 805 ) prior to measuring the UE signal level in step ( 810 ).
  • the choice between diversity and multiplexing may be made adaptively. This is illustrated in FIG. 9 .
  • the method 900 illustrated in FIG. 9 is the same as method 400 of FIG. 4 with the exception of step 940 , which is performed when the BS 120 determines that the UE 130 is not close to the edge, e.g., determines that the UE 130 is not within the threshold edge distance.
  • the BS 120 adaptively chooses the operation mode.
  • FIG. 10 illustrates an example process to implement step 940 to adaptively choose between diversity and multiplexing.
  • the BS 120 determines whether the UE 130 is located within a threshold base station distance from the base station 120 (step 1010 ). If so, the BS 120 chooses multiplexing for transmission from the base station 120 to the UE 130 when the UE 130 is determined to be located within the threshold base station distance (step 1020 ). Otherwise, the BS 120 chooses one of diversity and multiplexing based on spectral characteristics of a radio link between the BS 120 to the UE 130 (step 1030 ). Spectral characteristics can be the expected spectral efficiency and/or capacity computed at the base station from pilot measurements for each individual communication mode.
  • FIG. 11 illustrates a cell represented by the large solid circle.
  • the corresponding base is not shown, but it is assumed that the base station is centrally located.
  • FIG. 11 three regions are shown—the center region enclosed by smaller dashed circle, edge region defined between the outer solid circle and the larger dashed circle, and an intermediate region between the two dashed circles.
  • the interference level can change over time. Thus, it is possible that the interference, even within the cell edge region, will be low enough at some point so that multiplexing can be utilized.
  • the cell edge region can be viewed as a region in which diversity is assumed to achieve the best throughput is sufficiently accurate such that incurring the cost of determining the spectral characteristics for choosing the best mode is not warranted.
  • the cell edge region may be viewed to correspond to the YES branch in step 420 of FIGS. 4 and 9
  • the center region may be viewed to correspond to the YES branch in step 1010 in FIG. 10
  • the intermediate region may be viewed to correspond to the NO branch in step 1010 in FIG. 10 .
  • the rank is at least two in this region. While not shown, it should be realized that the center region can be even more finely subdivided into minimum rank 2 region, minimum rank 3 region, and so on.
  • FIG. 12 illustrates an example arrangement of a base station such as the BS 120 .
  • the BS 120 may include a communication unit 1210 , a UE location determination unit 1230 , and a communication mode determination unit 1240 .
  • FIG. 12 provides a logical view of the BS 120 , and thus, some or all units may be separate or may be combined physically in an integrated module. Also, the some or all units may be implemented through a combination of hardware, software, and firmware.
  • the BS 120 may include one or more processing units executing program instructions stored in a storage unit 1220 to perform the functions of any one or more the units 1210 , 1230 , and 1240 .
  • the program instructions may be provided through a non-transitory storage medium or in programmed in firmware.

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190141715A1 (en) * 2008-01-24 2019-05-09 Firetide, Inc. Channel assignment for wireless access networks

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102039343B1 (ko) * 2013-03-26 2019-11-01 삼성전자주식회사 무선 이동 통신 시스템에서 mcs 레벨 결정 방법 및 장치
US11019481B2 (en) 2018-11-20 2021-05-25 Cisco Technology, Inc. Dynamic cell boundary roaming management using client feedback

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050281189A1 (en) * 2004-06-16 2005-12-22 Samsung Electronics Co., Ltd. Method for transmitting/receiving data in mobile communication systems using an OFDMA scheme
US20060182063A1 (en) * 2002-03-22 2006-08-17 Nortel Networks Limited Soft handoff for OFDM
EP1715600A1 (fr) 2004-02-26 2006-10-25 Matsushita Electric Industrial Co., Ltd. DISPOSITIF DE POSTE MOBILE ET PROC D DE S L ECTION D’ANTENNE D’ MISSION DANS LE DISPOSITIF DE POSTE MOBILE
US20070153756A1 (en) * 2004-07-12 2007-07-05 Yutaka Kobayashi Radio bearer control method and radio base station
US20090190488A1 (en) 2008-01-28 2009-07-30 Beceem Communications Inc. Method of aiding uplink beamforming transmission
US20100267338A1 (en) * 2009-04-21 2010-10-21 Chunghwa Telecom Co., Ltd Method For Restraining Inter-Cell Interference In A Mobile Communication System

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060182063A1 (en) * 2002-03-22 2006-08-17 Nortel Networks Limited Soft handoff for OFDM
EP1715600A1 (fr) 2004-02-26 2006-10-25 Matsushita Electric Industrial Co., Ltd. DISPOSITIF DE POSTE MOBILE ET PROC D DE S L ECTION D’ANTENNE D’ MISSION DANS LE DISPOSITIF DE POSTE MOBILE
US20050281189A1 (en) * 2004-06-16 2005-12-22 Samsung Electronics Co., Ltd. Method for transmitting/receiving data in mobile communication systems using an OFDMA scheme
US20070153756A1 (en) * 2004-07-12 2007-07-05 Yutaka Kobayashi Radio bearer control method and radio base station
US20090190488A1 (en) 2008-01-28 2009-07-30 Beceem Communications Inc. Method of aiding uplink beamforming transmission
US20100267338A1 (en) * 2009-04-21 2010-10-21 Chunghwa Telecom Co., Ltd Method For Restraining Inter-Cell Interference In A Mobile Communication System

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190141715A1 (en) * 2008-01-24 2019-05-09 Firetide, Inc. Channel assignment for wireless access networks
US10616900B2 (en) * 2008-01-24 2020-04-07 Firetide, Inc. Channel assignment for wireless access networks
US11659580B2 (en) * 2008-01-24 2023-05-23 Firetide, Inc. Channel assignment for wireless access networks

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